1. Chemical Reactors

3. Batch Reactors

4. Characteristics
Reactor is charged via two holes in the top of the tank;
While reaction is carried out, nothing else is put in or taken out until the reaction is done;
Tank easily heated or cooled by jacket .
This type are used for a variety of process operations.
A typical batch reactor consists of a tank with an agitator and integral heating/cooling system.
These vessels may vary in size from less than 1 liter to more than 15,000 liters .
They are usually fabricated in steel, stainless steel, glass lined steel, glass or exotic alloy .

5. Kinds of Phases Present
Gas phase
Liquid phase
Liquid-Solid
CEB MKII Batch Reactor

6. Usage Small scale production Intermediate or one shot production
Pharmaceutical
Fermentation
Solids dissolution
Product mixing
Chemical reactions
Batch distillation
Crystallization
Liquid/liquid extraction
Polymerization

7. Advantages Disadvantages High conversion per unit volume for one pass
Flexibility of operation - same reactor can produce one product at a time and different product the next
Easy to clean
Disadvantages
High operating cost
Product quality more variable than with continuous operation

8. Sequential Batch Reactors (SBR)

11. Carbon Steel or Stainless Steel Reactors

12. Stainless steel reactors for chemical plant

14. "Glass Lined Reactors"

15. Reaction Vessel (Reactor)

16. Continuous Stirred Tank Reactors (CSTR)

17. Characteristics
Run at steady state with continuous flow of reactants and products;
The feed assumes a uniform composition throughout the reactor;
Exit stream has the same composition as in the tank.

19. Usage Kinds of Phases Present Liquid phase Gas-liquid reactions
Solid-liquid reactions
Usage
When agitation is required
Series configurations for different concentration stream.
CEM MK II CSTR

20. Advantages Disadvantages Continuous operation Good temperature control
Easily adapts to two phase runs
Good control
Simplicity of construction
Low operating (labor) cost
Easy to clean
Disadvantages
Lowest conversion per unit volume
By-passing and channeling possible with poor agitation

21. Semi-Batch reactor
Batch reactor

22. Stirred contained solids reactors

27. Plug Flow Reactors (PFR)

28. Characteristics Kinds of Phases Present
Arranged as one long reactor or many short reactors in a tube bank ;
No radial variation in reaction rate (concentration);
Concentration changes with length down the reactor.
Kinds of Phases Present
Primarily Gas Phase

29. Usage Large Scale Fast Reactions Homogeneous Reactions
Heterogeneous Reactions
Continuous Production
High Temperature

30. Advantages Disadvantages High conversion per unit volume
Low operating (labor) cost
Continuous operation
Good heat transfer
Disadvantages
Undesired thermal gradients may exist
Poor temperature control
Shutdown and cleaning may be expensive

31. Tubular reactor

32. Plug-flow reactors for Biomass Conversion

33. Industrial scale Reactor

35. Homogeneous Continuous Reactions (Plug Flow)

36. Reactive Distillation - Homogeneous
                                                                   .

37. Reactive Distillation - Heterogeneous

40. creating plug-flow conditions in reactors

41. Fixed bed reactors

43. Fluidized bed reactor
Fischer-Tropsch reaction convert synthesis gas into a mixture of alkanes and alkenes over Fe catalyst.

45. Four major chemical reactors
in petroleum refining

46. THE HUMAN REACTOR

47. Process Design

48. Matters for Design Consideration
Type of processing
Batch
Continuous
Semibatch or semicontinuous
Type and nature of reacting system
Simple
Complex (desirable,, undesirable products)
Stoichiometry
Phases, number of phases
Catalytic (choice of catalyst) or noncatalytic
Endothermic or exothermic
Possibility of equilibrium limitation

49. Cont. Type and size of reactor Mode of operation Batch
Continuous (stirred tank , tubular, tower/column, bed )
Mode of operation
Configurational (single-stage or multistage , axial or radial flow, arrangement of heat transfer surface, flow pattern, contacting pattern)
Thermal (adiabatic, isothermal , nonisothermal, nonadiabatic)
Use of recycle

50. Cont.. Process conditions Optimality T profile P profile
Feed (composition, rate)
Product (composition, rate)
Optimality
of process conditions
of size
of product distribution
of conversion
of cost (local, global context)

51. Cont… Control and stability of operation Socioeconomic
Instrumentation
Control variables
Sensitivity analysis
Catalyst life, deactivation, poisons
Socioeconomic
Cost
Environmental
Safety
Materials of constructional corrosion
Startup and shutdown procedures

52. Data Required Specifications general data Reactants Products
Throughput or capacity
general data
Rate data/parameters relating to reaction (rate law/s, heat transfer, mass transfer, pressure drop, equilibrium data, other physical property data, cost data)

53. Tools Available
The rational design of a chemical reactor is perhaps the most difficult equipment-design task of a chemical engineer.
Rate processes and rate laws
Reaction kinetics
Diffusion and mass transfer
Heat transfer
Fluid mechanics (flow patterns , mixing, pressure drop)
Conservation and balance equations
Mass balances (including stoichiometry)
Continuity equation
Energy balance (including energetics of reaction)
Thermochemistry

54. Cont. Equilibrium Mathematics Reaction equilibrium Phase equilibrium
Development of a reactor model
Analytical or numerical methods for solution of equations
Simulation statistical analysis of rate data

55. Cont.. Computers and computer software Process economics
Use of a PC, workstations, etc., coupled with software packages to solve sets of algebraic and/or differential equations, and to perform statistical analyses necessary for implementation of a reactor model for design or for assessment of reactor performance
Software (spreadsheet packages, simulation software, numerical equation solvers, computer algebra system)
Process economics

56. Mechanical Design Impeller or agitator design (as in a stirred tank)
Power requirement (for above)
Reactor-as-pressure-vessel design
Wall thickness
Over-pressure relief
Fabrication
Support-structure design
Maintenance features